CA2683122A1 - Therapy targeting cathepsin s - Google Patents

Abstract

Described are methods of treating a condition associated with angiogenesis comprising administration of an antibody molecule which specifically binds cathepsin S. but does not inhibit the proteolytic activity of cathepsin S. also provided are antibody molecules for use in such methods.

Description

1 "Antibody and Uses Thereof"

3 Field of the Invention This application relates to methods of treatment of 6 conditions and diseases related to angiogenesis, and 7 compositions for use in such methods.

9 Background to the Invention 11 Angiogenesis, the development of microvasculature, 12 is an integral process within many normal 13 physiological processes such as normal development 14 and wound healing. Angiogenesis is characterised by the stimulation of endothelial cells to form primary 16 blood vessels where a non-clarified complex 17 interplay exists between the endothelial cells, 18 surrounding microenvironment and a range of pro and 19 anti-angiogenic factors. However, uncontrolled or inappropriate angiogenesis is accepted as an 21 underlying factor to the pathology of a wide range 22 of diseases including tumour progression and ocular 23 disease.

Pathological Ocular Neovascularisation 27 Unregulated angiogenesis in the eye is considered 28 the leading cause of blindness, in a wide range of 29 conditions including corneal graft rejection, neovascularization following injury or infection, 31 diabetic retinopathy, retrolental fibroplasia and 32 neovascular glaucoma.

2 Molecules such as vascular endothelial growth factor 3 (VEGF) have been shown to play instrumental roles in 4 promotion of angiogenesis and indeed the sequestering of this molecule using antibodies has 6 been established as a therapeutic strategy for the 7 prevention of pathological angiogenesis.

9 However, other proteins, such as cathepsin S, have also been shown to be upregulated in angiogenic 11 sites.

13 Cathepsin S (Cat S) is a member of the papain 14 superfamily of lysosomal cysteine proteases. To date, eleven human cathepsins have been identified, 16 but the specific in vivo roles of each are still to 17 be determined (Katunuma et al, 2003). Cathepsins B, 18 L, H, F, 0, X and C are expressed in most cells, 19 suggesting a possible role in regulating protein turnover, whereas Cathepsins S, K, W and V are 21 restricted to particular cells and tissues, 22 indicating that they may have more specific roles 23 (Kos et al, 2001; Berdowska, 2004).

Cat S was originally identified from bovine lymph 26 nodes and spleen and the human form cloned from a 27 human macrophage cDNA library (Shi et al, 1992). The 28 gene encoding Cat S is located on human chromosome 29 1q21. The 996 base pair transcript encoded by the Cat S gene, is initially translated into an 31 unprocessed precursor protein with a molecular 32 weight of 37.5 kDa. The unprocessed protein is 1 composed of 331 amino acids; a 15 amino acid signal 2 peptide, a 99 amino acid pro-peptide sequence and a 3 217 amino acid peptide. Cat S is initially expressed 4 with a signal peptide that is removed after it enters the lumen of the endoplasmic reticulum. The 6 propeptide sequence binds to the active site of the 7 protease, rendering it inactive until it has been 8 transported to the acidic endosomal compartments, 9 after which the propeptide sequence is removed and the protease is activated (Baker et al, 2003).

12 Cat S has been identified as a key enzyme in major 13 histocompatibility complex class II (MHC-II) 14 mediated antigen presentation, by cleavage of the invariant chain, prior to antigen loading. Studies 16 have shown that mice deficient in Cat S have an 17 impaired ability to present exogenous proteins by 18 APC's (Nakagawa et al, 1999). The specificity of Cat 19 S in the processing of the invariant chain Ii, allows for Cat S specific therapeutic agents in the 21 treatment of conditions such as asthma and 22 autoimmune disorders (Chapman et al, 1997).

24 Pathological association of Cat S
26 Alterations in protease control frequently underlie 27 many human pathological processes. The deregulated 28 expression and activity of the lysosomal cysteine 29 protease Cathepsin S has been linked to a range of conditions including neurodegenerative disorders, 31 autoimmune diseases and certain malignancies.

1 Cat S upregulation has been linked to several 2 neurodegenerative disorders. It is believed to have 3 a role in the production of the (3 peptide (A(3) from 4 the amyloid precursor protein (APP) (Munger et al, 1995) and its expression has been shown to be 6 upregulated in both Alzheimer's Disease and Down's 7 Syndrome (Lemere et al, 1995). Cat S may also have a 8 role in Multiple Sclerosis through the ability of 9 Cat S to degrade myelin basic protein, a potential autoantigen implicated in the pathogenesis of MS
11 (Beck et al, 2001) and in Creutzfeldt - Jakob 12 disease (CJD) patients, Cat S expression has been 13 shown to increase more than four fold (Baker et al, 14 2002) 16 Aberrant Cat S expression has also been associated 17 with atherosclerosis. Cat S expression is negligible 18 in normal arteries, yet human atheroma display 19 strong immunoreactivity (Sukhova et al, 1998).
Further studies using knockout mice, deficient in 21 both Cat S and the LDL-receptor, were shown to 22 develop significantly less atherosclerosis (Sukhova 23 et al, 2003). Further research has linked Cat S
24 expression with inflammatory muscle disease and rheumatoid arthritis. Muscle biopsy specimens from 26 patients with inflammatory myopathy had a 10 fold 27 increase in Cat S expression compared to control 28 muscle sections (Wiendl et al, 2003), and levels of 29 Cat S expression were significantly higher in synovial fluid from patients with rheumatoid 31 arthritis compared to those with osteoarthritis 32 (Hashimoto et al, 2001).

2 The association of CatS with angiogenesis was first 3 shown in vitro using CatS deficient endothelial 4 cells (Shi et al, 2003). Microvascular endothelial 5 cells (ECs) have been shown to secrete proteases, 6 permitting penetration of the vascular basement 7 membrane as well as the interstitial extracellular 8 matrix. Treatment of cultured ECs with inflammatory 9 cytokines or angiogenic factors stimulated expression of CatS, and its inhibition reduced 11 microtubule formation. CatS -/- mice displayed 12 defective microvessel development during wound 13 repair in comparison to wild-type controls (Shi et 14 al, 2003) 16 Further examination of the role of CatS in 17 angiogenesis and tumour growth was demonstrated in a 18 transgenic mouse model for pancreatic islet cell 19 carcinoma. CatS-/- mice were found to develop significantly smaller tumours and fewer angiogenic 21 islets in comparison to the CatS+/+ control mice 22 (Gocheva et al., 2006). Insight to the molecular 23 mechanism underpinning this phenotype was 24 subsequently provided by evidence that CatS could cleave and inactivate anti-angiogenic peptides and 26 promote the generation of active pro-angiogenic 27 fragments (Wang et al, 2006).

29 Finally, the role of CatS in malignancy and angiogenesis has also been examined in a murine 31 model of hepatocellular carcinoma. Microarray 32 analysis on normal ECs and those extracted from 1 tumour model showed that CatS gene expression was 2 74-fold greater in the tumour ECs compared to the 3 normal cells (Ryschich et al, 2006).

The generation of inhibitors specifically targeting 6 the proteolytic cativity of Cat S have potential as 7 therapeutic agents for alleviations of the symptoms 8 associated with the activity of this protease.

Inhibition of Cat S

12 When proteases are over-expressed, therapeutic 13 strategies have focused on the development of 14 inhibitors to block the activity of these enzymes.
The generation of specific small molecule inhibitors 16 to the cathepsins have proved difficult in the past, 17 due to problems with selectivity and specificity.

18 The dipeptide OG-keto-(3-aldehydes developed as potent 19 reversible inhibitors to Cat S by Walker et al, had the ability to inhibit Cat B and L, albeit with less 21 efficiency (Walker et al, 2000), and the Cat S
22 inhibitor 4-Morpholineurea-Leu-HomoPhe-vinylsulphone 23 (LHVS) has also been shown to inhibit other 24 cathepsins when used at higher concentrations (Palmer et al, 1995).

27 Co-pending application PCT/GB2006/001314, filed 10 28 April 2006, and which shares an inventor with the 29 present application, describes a monoclonal antibody with specificity for cathepsin S which 31 potently inhibits the proteolytic activity of 32 cathepsin S. This antibody was shown to inhibit 1 tumour cell invasion and angiogenesis.
2 PCT/GB2006/001314 teaches that this is the first 3 demonstration of a cathepsin S specific antibody 4 directly inhibiting the protease activity of cathepsin S and thus uniquely enables the use of 6 such antibodies as active therapeutic agents with a 7 wide range of applications.

9 Other than as described in PCT/GB2006/001314, there have been no reports of anti Cathepsin S antibodies 11 which have demonstrable therapeutic potential.
12 Notably, although some antibodies which bind certain 13 particular proteins have been shown to have some 14 effect on the normal activity of the particular protein, this has not previously been demonstrated 16 for any antibody which binds Cathepsin S. Indeed, 17 in PCT/GB2006/001314, it is shown that control 18 antibodies which bound cathepsin S but which did not 19 affect proteolytic activity had no effect on tumour cell invasion.

22 Summary of the Invention 24 The present inventors have studied the effects of a number of cathepsin S antibodies on a number of 26 models of disease.

28 The present inventors have shown for the first time 29 that antibodies, which have specificity for cathepsin S, but which do not inhibit the 31 proteolytic activity of cathepsin S, nevertheless 32 act as potent inhibitors of angiogenesis. This was 1 particularly surprising to the inventors given that, 2 as taught in PCT/GB2006/001314, it was believed that 3 to counteract the pathological effects of 4 dysregulation of cathepsin S activity, strategies are required which inhibit the proteolytic effects 6 of cathepsin S. Furthermore, although the use of 7 antibodies to sequester proteins has been suggested 8 as a therapeutic strategy for some proteins, e.g.
9 VEGF, such a strategy has not, until now, been considered as feasible for the treatment of diseases 11 associated with cathepsin S activity.

13 Accordingly, in a first aspect, the present 14 invention provides a method of treating a condition associated with angiogenesis in a patient in need of 16 treatment thereof, said method comprising 17 administration of an antibody molecule or a nucleic 18 acid encoding said antibody molecule to said 19 patient, wherein said antibody molecule specifically binds cathepsin S but does not inhibit 21 the proteolytic activity of cathepsin S.

23 According to a second aspect of the invention, there 24 is provided the use of an antibody molecule or a nucleic acid encoding said antibody molecule in the 26 preparation of a medicament for the treatment of a 27 condition associated with angiogenesis, wherein 28 said antibody molecule specifically binds cathepsin 29 S but does not inhibit the proteolytic activity of cathepsin S.

1 The invention may be used in the treatment of any 2 disease or condition in which angiogenesis plays a 3 part in the pathology of the disease. Such 4 conditions and diseases include, but are not limited to cancer, inflammatory conditions, for example 6 inflammatory muscle disease, rheumatoid arthritis 7 and asthma, ocular diseases, atherosclerosis and 8 cancer.

Moreover, the demonstration that antibody molecules 11 which specifically bind cathepsin S but do not 12 inhibit the proteolytic activity of cathepsin S
13 nevertheless inhibit angiogenesis enables the use of 14 such antibody molecules in the treatment of other conditions associated with cathepsin S.

17 In a third aspect, there is provided method of 18 treating a condition associated with activity of 19 Cathepsin S in a patient in need of treatment thereof, said method comprising administration of an 21 antibody molecule or nucleic acid encoding the 22 antibody molecule to said patient, wherein said 23 antibody molecule specifically binds cathepsin S but 24 does not inhibit the proteolytic activity of cathepsin S.

27 Also provided as a fourth aspect is the use of an 28 antibody molecule or nucleic acid encoding the 29 antibody molecule wherein said antibody molecule specifically binds cathepsin S but does not inhibit 31 the proteolytic activity of cathepsin S in the 32 preparation of a medicament for the treatment of a 1 condition associated with aberrant activity or 2 expression of cathepsin S.

4 The invention may be used in the treatment of any 5 condition with which aberrant activity of cathepsin 6 S is associated, in particular conditions associated 7 with expression of cathepsin S. For example, 8 conditions in which the invention may be used 9 include, but are not limited to neurodegenerative 10 disorders, for example Alzheimer's disease and 11 multiple sclerosis, autoimmune disorders, and other 12 diseases associated with excessive, deregulated or 13 inappropriate angiogenesis.

In the invention, any suitable anti-cathepsin S
16 antibody molecule, which does not inhibit the 17 proteolytic activity of cathepsin S, but which 18 inhibits angiogenesis, may be used.

Such antibody molecules and nucleic acids encoding 21 such antibody molecules constitute a fifth 22 independent aspect of the invention.

24 As described in the Examples, the inventors have identified the binding region on Cathepsin S to 26 which the 1E4 antibody specifically binds. The 27 binding region has the amino acid sequence shown as 28 Sequence ID No: 1:

ELPYGREDVLKEAVANKGPVSVGVDARHP (Sequence ID No: 1) 1 Accordingly, in a sixth aspect of the invention, 2 there is provided an isolated polypeptide, wherein 3 said polypeptide consists of a polypeptide sequence 4 having at least 60%, homology to Sequence ID No: 1.
In one embodiment, the polypeptide sequence consists 6 of a polypeptide sequence having the amino acid 7 sequence shown as Sequence ID No: 1.

9 Thus, in one embodiment of the fifth aspect of the invention, the antibody molecule is an antibody 11 molecule which has binding specificity for the 12 polypeptide of the sixth aspect of the invention.

14 In one embodiment of the invention, the antibody molecule is a 1E4 antibody or a fragment or variant 16 thereof.

18 The antibody molecule may be an antibody, for 19 example a whole antibody. In one alternative embodiment, the antibody molecule may be an antibody 21 fragment such as an scFv.

23 Related antibody molecules which also inhibit 24 angiogenesis but which do not inhibit the proteolytic activity of cathepsin S and which 26 optionally have similar or greater binding 27 specificity may also be used as the antibody 28 molecule in the present invention.

Such antibody molecules may comprise at least one of 31 the CDRs of the VH chain of the 1E4 antibody and/or 32 at least one of the CDRs of the VH chain of the 1E4 1 antibody in which 5 or less, for example 4, 3, 2, or 2 1 amino acid substitutions have been made in at 3 least one CDR and wherein the antibody molecule 4 retains the ability to inhibit angiogenesis but does not have ability to inhibit the proteolytic activity 6 of cathepsin S.

8 In one embodiment of the invention, the antibody 9 molecule of and for use in the invention has the ability to inhibit tumour cell invasion.

12 According to a further aspect of the invention, 13 there is provided an antibody molecule or a nucleic 14 acid encoding said antibody molecule for use in medicine, wherein said antibody molecule 16 specifically binds cathepsin S but does not inhibit 17 the proteolytic activity of cathepsin S

19 Another aspect of the invention is a pharmaceutical composition comprising an antibody molecule or 21 nucleic acid encoding the antibody molecule wherein 22 said antibody molecule specifically binds cathepsin 23 S but does not inhibit the proteolytic activity of 24 cathepsin S.
26 Preferred and alternative features of each aspect of 27 the invention are as for each of the other aspects 28 mutatis mutandis unless the context demands 29 otherwise.
31 Detailed Description 1 Antibody molecules 3 In the context of the present invention, an antibody 4 molecule (or specific binding member) is a molecule which has binding specificity for another molecule, 6 in particular for cathepsin S. The antibody molecule 7 may be an antibody or fragment thereof.

9 An antibody should be understood to refer to an immunoglobulin or part thereof or any polypeptide 11 comprising a binding domain which is, or is 12 homologous to, an antibody binding domain. Specific 13 antibody molecules include but are not limited to 14 polyclonal, monoclonal, monospecific, polyspecific antibodies and fragments thereof and chimeric 16 antibodies comprising an immunoglobulin binding 17 domain fused to another polypeptide. Antibody 18 mimetics are also encompassed by antibody molecules.

Intact (whole) antibodies comprise an immunoglobulin 21 molecule consisting of heavy chains and light 22 chains, each of which carries a variable region 23 designated VH and VL, respectively. The variable 24 region consists of three complementarity determining regions (CDRs, also known as hypervariable regions) 26 and four framework regions (FR) or scaffolds. The 27 CDR forms a complementary steric structure with the 28 antigen molecule and determines the specificity of 29 the antibody.
31 Fragments of antibodies may retain the binding 32 ability of the intact antibody and may be used in 1 place of the intact antibody. Accordingly, for the 2 purposes of the present invention, unless the 3 context demands otherwise, the term "antibody 4 molecules" should be understood to encompass antibody fragments. Examples of antibody fragments 6 include Fab, Fab' , F (ab') 2, Fd, dAb, and Fv 7 fragments, scFvs, bispecific scFvs, diabodies, 8 linear antibodies (see US patent 5, 641, 870, 9 Example 2 ; Zapata etal., Protein Eng 8 (10) 1057-1062 [1995]) ; single-chain antibody molecules;
11 and multispecific antibodies formed from antibody 12 fragments.

14 The Fab fragment consists of an entire L chain ( VL
and CL), together with VH and CH1. Fab' fragments 16 differ from Fab fragments by having additional few 17 residues at the carboxy terminus of the CH1 domain 18 including one or more cysteines from the antibody 19 hinge region. The F (ab') 2 fragment comprises two disulfide linked Fab fragments.

22 Fd fragments consist of the VH and CH1 domains.

24 Fv fragments consist of the VL and VH domains of a single antibody.

27 Single-chain Fv fragments are antibody fragments 28 that comprise the VH and VL domains connected by a 29 linker which enables the scFv to form an antigen binding site. (see Pluckthun in The Pharmacology of 31 Monoclonal Antibodies, vol.113, Rosenburg and Moore 32 eds., Springer-Verlag, New York, pp. 269-315 (1994).

2 Diabodies are small antibody fragments prepared by 3 constructing scFv fragments (see preceding 4 paragraph) with short linkers (about 5-10 residues) 5 between the VH and VL domains such that inter-chain 6 but not intra-chain pairing of the V domains is 7 achieved, resulting in a multivalent fragment, i.e.
8 a fragment having two antigen-binding sites (see, 9 for example, EP 404 097 ; WO 93/11161 ; and 10 Hollinger et al., Proc. Natl. Acad. Sci. USA, 90 11 6444-6448 (1993)) 13 Further encompassed by fragments are individual 14 CDRs.
16 As described above, the antibody molecules of and 17 for use in the present invention are not limited to 18 the 1E4 antibody, but also extends to other 19 antibodies which maintain the ability to inhibit angiogenesis but which do not inhibit the 21 proteolytic activity of Cat S. Thus, the CDR amino 22 acid sequences of such antibodies in which one or 23 more amino acid residues are modified may also be 24 used as the CDR sequence. The modified amino acid residues in the amino acid sequences of the CDR
26 variant are preferably 30% or less, more preferably 27 20% or less, most preferably 10% or less, within the 28 entire CDR. Such variants may be provided using the 29 teaching of the present application and techniques known in the art. The CDRs may be carried in a 31 framework structure comprising an antibody heavy or 32 light chain sequence or part thereof. Preferably 1 such CDRs are positioned in a location corresponding 2 to the position of the CDR(s) of naturally occurring 3 VH and VL domains. The positions of such CDRs may 4 be determined as described in Kabat et al, Sequences of Proteins of Immunological Interest, US Dept of 6 Health and Human Services, Public Health Service, 7 Nat'l Inst. of Health, NIH Publication No. 91-3242, 8 1991 and online at www.kabatdatabase.com 9 http://immuno.bme.nwu.edu.
11 Furthermore, modifications may alternatively or 12 additionally be made to the Framework Regions of the 13 variable regions. Such changes in the framework 14 regions may improve stability and reduce immunogenicity of the antibody.

17 The antibodies of the invention herein include 18 "chimeric" antibodies in which a portion of the 19 heavy and/or light chain is identical with or homologous to corresponding sequences in antibodies 21 derived from a particular species or belonging to a 22 particular antibody class or subclass, while the 23 remainder of the chain (s) is identical with or 24 homologous to corresponding sequences in antibodies derived from another species or belonging to another 26 antibody class or subclass, as well as fragments of 27 such antibodies, so long as they exhibit the desired 28 biological activity (see U. S. Patent No. 4, 816, 29 567 ; and Morrison et al., Proc. Natl. Acad. Sci.
USA, 81 : 6851-6855 (1984)). Chimeric antibodies of 31 interest herein include "primatized"antibodies 32 comprising variable domain antigen-binding sequences 1 derived from a non-human primate(e. g. Old World 2 Monkey, Ape etc), and human constant region 3 sequences.

Production Of Antibodies 7 Antibody molecules of and for use in the present 8 invention may be produced in any suitable way, 9 either naturally or synthetically. Such methods may include, for example, traditional hybridoma 11 techniques (Kohler and Milstein (1975) Nature, 256 12 :495-499), recombinant DNA techniques (see e.g. U.
13 S. Patent No. 4,816, 567), or phage display 14 techniques using antibody libraries (see e.g.
Clackson et al. (1991) Nature, 352: 624-628 and 16 Marks et al. (1992) Bio/ Technology, 10: 779-783).
17 Other antibody production techniques are described 18 in Antibodies: A Laboratory Manual, eds. Harlow et 19 al., Cold Spring Harbor Laboratory, 1988.
21 Traditional hybridoma techniques typically involve 22 the immunisation of a mouse or other animal with an 23 antigen in order to elicit production of lymphocytes 24 capable of binding the antigen. The lymphocytes are isolated and fused with a a myeloma cell line to 26 form hybridoma cells which are then cultured in 27 conditions which inhibit the growth of the parental 28 myeloma cells but allow growth of the antibody 29 producing cells. The hybridoma may be subject to genetic mutation, which may or may not alter the 31 binding specificity of antibodies produced.
32 Synthetic antibodies can be made using techniques 1 known in the art (see, for example, Knappik et al, 2 J. Mol. Biol. (2000) 296, 57-86 and Krebs et al, J.
3 Immunol. Meth. (2001) 2154 67-84.

Modifications may be made in the VH, VL or CDRs of 6 the antibody molecules, or indeed in the FRs using 7 any suitable technique known in the art. For 8 example, variable VH and/or VL domains may be 9 produced by introducing a CDR, e.g. CDR3 into a VH
or VL domain lacking such a CDR. Marks et al.
11 (1992) Bio/ Technology, 10: 779-783 describe a 12 shuffling technique in which a repertoire of VH
13 variable domains lacking CDR3 is generated and is 14 then combined with a CDR3 of a particular antibody to produce novel VH regions. Using analogous 16 techniques, novel VH and VL domains comprising CDR
17 derived sequences of the present invention may be 18 produced.

Alternative techniques of producing variant 21 antibodies of the invention may involve random 22 mutagenesis of gene(s) encoding the VH or VL domain 23 using, for example, error prone PCR (see Gram et al, 24 1992, P.N.A.S. 89 3576-3580. Additionally or alternatively, CDRs may be targeted for mutagenesis 26 e.g. using the molecular evolution approaches 27 described by Barbas et al 1991 PNAS 3809-3813 and 28 Scier 1996 J Mol Biol 263 551-567.

Having produced such variants, antibodies and 31 fragments may be tested for binding to Cat S and for 1 the ability to inhibit the proteolytic activity of 2 cathepsin S.

4 As described herein, the inventors have demonstrated that antibody molecules according to the invention 6 have an anti-angiogenic effect. This therefore 7 enables the use of the antibody molecules of the 8 invention as active therapeutic agents.
9 Accordingly in one embodiment of the invention, the antibody molecule is a "naked" antibody molecule. A
11 "naked" antibody molecule is an antibody molecule 12 which is not conjugated with an "active therapeutic 13 agent".

In the context of the present application, an 16 "active therapeutic agent" is a molecule or atom 17 which is conjugated to an antibody moiety (including 18 antibody fragments, CDRs etc) to produce a 19 conjugate. Examples of such "active therapeutic agents" include drugs, toxins, radioisotopes, 21 immunomodulators, chelators, boron compounds , dyes, 22 nanoparticles etc.

24 In another embodiment of the invention, the antibody molecule is in the form of an immunoconjugate, 26 comprising an antibody fragment conjugated to an 27 "active therapeutic agent".

29 Methods of producing immunoconjugates are well known in the art; for example, see U. S. patent No.
31 5,057,313, Shih et al., Int. J. Cancer 41: 832-839 32 (1988); Shih et al., Int. J.Cancer 46: 1101-1106 1 (1990), Wong, Chemistry Of Protein Conjugation And 2 Cross-Linking (CRC Press 1991); Upeslacis et al., 3 "Modification of Antibodies by Chemical Methods,"in 4 Monoclonal Antibodies: Principles And Applications, 5 Birch et al. (eds.), pages 187-230 (Wiley-Liss, Inc.
6 1995); Price, "Production and Characterization of 7 Synthetic Peptide-Derived Antibodies," in Monoclonal 8 Antibodies: Production, Engineering And Clinical 9 Application, Ritter et al.(eds.), pages 60-84 10 (Cambridge University Press 1995).

12 The antibody molecules of and for use in the 13 invention may comprise further modifications. For 14 example the antibodies can be glycosylated, 15 pegylated, or linked to albumin or a 16 nonproteinaceous polymer. The antibody molecule may 17 be in the form of an immunoconjugate.

19 Antibodies of the invention may be labelled. Labels 20 which may be used include radiolabels, enzyme labels 21 such as horseradish peroxidase, alkaline 22 phosphatase, or biotin.

24 As noted above, antibodies of and for use in the methods of the invention do not inhibit the 26 proteolytic effct of cathepsin S. The ability of an 27 antibody molecule to inhibit the proteolytic 28 activity of cathepsin S may be tested using any 29 suitable method. For example the ability of an antibody molecule to inhibit the proteolytic 31 activity of cathepsin S may be tested using a 32 fluorimetric assay. In such an assay, any suitable 1 fluorigenic substrate may be used, for example Cbz-2 Val-val-Arg-AMC. An antibody molecule is considered 3 td inhibit the proteolytic activity of cathepsin S
4 if it has the ability to inhibit its activity by a significant amount. For example, in one embodiment, 6 the antibody molecule is considered not to inhibit 7 the proteolytic activity if it inhibits the 8 proteolytic activity by no more than 10%, for 9 example no more than 5%, such as no more than 2%, for example less than 1%, such as 0% compared to an 11 appropriate control antibody known to inhibit the 12 proteolytic effect of cathepsin S:

14 The ability of an antibody molecule to inhibit angiogenesis may be tested using any suitable assay 16 known in the art. Many in vitro and in vivo assays 17 are known in the art. These include Matrigel plug 18 and corneal neovascularization assays, the in 19 vivo/in vitro chick chorioallantoic membrane (CAM) assay, and the in vitro cellular (proliferation, 21 migration, tube formation) and organotypic (aortic 22 ring) assays, the chick aortic arch and the Matrigel 23 sponge assays. Further details of such assays may 24 be found, for example, in Auerbach et al, Clinical Chemistry 49: 32-40, 2003; 10.1373/49.1.32. Further 26 details are also provided in the Examples.

28 The ability of an antibody molecule to inhibit 29 tumour cell invasion may be tested using any suitable invasion assay known in the art. For 31 example, such ability may be tested using a modified 32 Boyden chamber as described in the Examples. The SUBSTITUTE SHEET (RULE 26) 1 antibody molecule may be tested using any suitable 2 tumour cell line, for example a prostate carcinoma 3 cell line, e.g. PC3, an astrocytoma cell line 4 e.g.U251mg, a colorectal carcinoma cell line, e.g.
HCT116, or a breast cancer cell line, e.g. MDA-MB-6 231 or MCF7. An antibody molecule is considered to 7 inhibit tumour cell invasion if it has the ability 8 to inhibit invasion by a statistically significant 9 amount. For example, in one embodiment, the antibody molecule is able to inhibit invasion by at 11 least 10%, for example at least 25%, at least 50%, 12 at least 60%, at least 70%, at least 80% or at least 13 90% when compared to an appropriate control 14 antibody.
16 In one embodiment of the invention, an antibody 17 molecule for use in the invention may have 18 inhibitory activity( for example to inhibit the 19 angiogenesis) with a potency of at least 25%, for example at least 40%, for example at least 50% of 21 the inhibitory potency of antibody 1E4.

23 Polypepti8es As described above, the inventors have identified 26 the binding region to which the 1E4 antibody binds.
27 Accordingly, the invention extends to an isolated 28 polypeptide, wherein said polypeptide consists of a 29 polypeptide sequence having at least 60%, homology, for example at least 70% homology, at least 80%
31 homology, at least 90% homology, or at least 95%
32 homology to Sequence ID No: 1. In one embodiment, SUBSTITUTE SHEET (RULE 26) 1 the polypeptide sequence consists of a polypeptide 2 sequence having the amino acid sequence shown as 3 Sequence ID No: 1.

ELPYGREDVLKEAVANKGPVSVGVDARHP (Sequence ID No: 1) 7 Thus a variant polypeptide in accordance with the 8 present invention may include within the sequence 9 shown as Sequence ID No: 1, a single amino acid change or 2, 3, 4, 5, 6, 7, 8, or 9 changes, or 11 about 10, 15, changes. In addition to one or more 12 changes within the amino acid sequence shown, a 13 variant polypeptide may include additional amino 14 acids at the C terminus and/or N-terminus.
16 Homology (i.e. similarity or identity) may be as 17 defined using sequence comparisons are made using 18 FASTA and FASTP (see Pearson & Lipman, 1988. Methods 19 in Enzymology 183 : 6398). Parameters are preferably set, using the default matrix, as follows :
21 Gapopen (penalty for the first residue in a gap) .-22 12 for proteins/-16 for DNA
23 Gapext (penalty for additional residues in a gap) .-24 2 for proteins/-4 for DNA
KTUP word length : 2 for proteins/6 for DNA.
26 Homology may be at the nucleotide sequence and/or 27 encoded amino acid sequence level.

29 Naturally, regarding nucleic acid variants, changes to the nucleic acid which make no difference to the 31 encoded polypeptide (i.e.'degeneratively 1 equivalent') are included within the scope of the 2 present invention.

Changes to a sequence, may be by one or more of 6 addition, insertion, deletion or substitution of one 7 or more nucleotides in the nucleic acid, leading to 8 the addition, insertion, deletion or substitution of 9 one or more amino acids in the encoded polypeptide.
Changes may be by way of conservative variation, i.
11 e. substitution of one hydrophobic residue such as 12 isoleucine, valine, leucine or methionine for 13 another, or the substitution of one polar residue 14 for another, such as arginine for lysine, glutamic for aspartic acid, or glutamine for asparagine. As 16 is well known to those skilled in the art, altering 17 the primary structure of a polypeptide by a 18 conservative substitution may not significantly 19 alter the activity of that peptide because the side-chain of the amino acid which is inserted into the 21 sequence may be able to form similar bonds and 22 contacts as the side chain of the amino acid which 23 has been substituted out. This is so even when the 24 substitution is in a region which is critical in determining the peptides conformation.

27 Also included are variants having non-conservative 28 substitutions. As is well known to those skilled in 29 the art, substitutions to regions of a peptide which are not critical in determining its conformation may 31 not greatly affect its activity because they do not 1 greatly alter the peptide's three dimensional 2 structure.

4 In regions which are critical in determining the 5 peptides conformation or activity such changes may 6 confer advantageous properties on the polypeptide.
7 Indeed, changes such as those described above may 8 confer slightly advantageous properties on the 9 peptide e. g. altered stability or specificity.
11 Nucleic Acid 13 Nucleic acid of and for use in the present invention 14 may comprise DNA or RNA. It may be produced recombinantly, synthetically, or by any means 16 available to those in the art, including cloning 17 using standard techniques.

19 The nucleic acid may be inserted into any appropriate vector. A vector comprising a nucleic 21 acid of the invention forms a further aspect of the 22 present invention. In one embodiment the vector is 23 an expression vector and the nucleic acid is 24 operably linked to a control sequence which is capable of providing expression of the nucelic acid 26 in a host cell. A variety of vectors may be used.
27 For example, suitable vectors may include viruses 28 (e. g. vaccinia virus, adenovirus,etc.), 29 baculovirus); yeast vectors, phage, chromosomes, artificial chromosomes, plasmids, or cosmid DNA.

1 The vectors may be used to introduce the nucleic 2 acids of the invention into a host cell. A wide 3 variety of host cells may be used for expression of 4 the nucleic acid of the invention. Suitable host cells for use in the invention may be prokaryotic or 6 eukaryotic. They include bacteria, e.g. E. coli, 7 yeast, insect cells and mammalian cells. Mammalian 8 cell lines which may be used include Chinese hamster 9 ovary cells, baby hamster kidney cells, NSO mouse melanoma cells, monkey and human cell lines and 11 derivatives thereof and many others.
12 A host cell strain that modulates the expression of, 13 modifies, and/or specifically processes the gene 14 product may be used. Such processing may involve glycosylation, ubiquitination, disulfide bond 16 formation and general post-translational 17 modification.

19 Accordingly, the present invention also provides a host cell, which comprises one or more nucleic acid 21 or vectors of the invention.

23 Also encompassed by the invention is a method of 24 production of an antibody molecule of the invention, the method comprising culturing a host cell 26 comprising a nucleic acid of the invention under 27 conditions in which expression of the antibody 28 molecules from the nucleic acid occurs and, 29 optionally, isolating and/or purifying the antibody molecule.

1 For further details relating to known techniques and 2 protocols for manipulation of nucleic acid, for 3 example, in preparation of nucleic acid constructs, 4 mutagenesis, sequencing, introduction of DNA into cells and gene expression, and analysis of proteins, 6 see, for example, Current Protocols in Molecular 7 Biology, 5th ed.,Ausubel et al. eds., John Wiley &
8 Sons, 2005 and, Molecular Cloning: a Laboratory 9 Manual: 3rd edition Sambrook et al., Cold Spring Harbor Laboratory Press, 2001.

12 Treatment 13 The antibody molecules and nucleic acids of the 14 invention may be used in the treatment of a number of medical conditions.

17 Treatment" includes any regime that can benefit a 18 human or non-human animal. The treatment may be in 19 respect of an existing condition or may be prophylactic (preventative treatment). Treatment may 21 include curative, alleviation or prophylactic 22 effects.

24 The antibody molecules and nucleic acids of the invention may be used in the treatment of a variety 26 of condition and disorders. These include 27 atherosclerosis and neoplastic disease, 28 neurodegenerative disorders, autoimmune diseases, 29 cancer, inflammatory disorders, asthma, and atherosclerosis, and pain.

1 Neurodegenerative disorders which may be treated 2 using the antibody molecules, nucleic acids and 3 methods of the invention include, but are not 4 limited to, Alzheimer's Disease, Multiple Sclerosis and Creutzfeldt - Jakob disease.

7 Autoimmune diseases for which the invention may be 8 used include inflammatory muscle disease and 9 rheumatoid arthritis.
11 The antibody molecules, nucleic acids and methods of 12 the invention may also be used in the treatment of 13 cancers.

"Treatment of cancer" includes treatment of 16 conditions caused by cancerous growth and/or 17 vascularisation and includes the treatment of 18 neoplastic growths or tumours. Examples of tumours 19 that can be treated using the invention are, for instance, sarcomas, including osteogenic and soft 21 tissue sarcomas, carcinomas, e.g., breast-, lung-, 22 bladder-, thyroid-, prostate-, colon-, rectum-, 23 pancreas-, stomach-, liver-, uterine-, prostate 24 cervical and ovarian carcinoma, non-small cell lung cancer, hepatocellular carcinoma, lymphomas, 26 including Hodgkin and non-Hodgkin lymphomas, 27 neuroblastoma, melanoma, myeloma, Wilms tumor, and 28 leukemias, including acute lymphoblastic leukaemia 29 and acute myeloblastic leukaemia, astrocytomas, gliomas and retinoblastomas.

1 The invention may be particularly useful in the 2 treatment of existing cancer and in the prevention 3 of the recurrence of cancer after initial treatment 4 or surgery.
6 The antibody molecules, nucleic acids and 7 compositions of the invention may also be used in 8 the treatment of other disorders mediated by or 9 associated with angiogenesis. Such conditions include, for example, tumours, various autoimmune 11 disorders, hereditary disorders, ocular disorders.

13 Particular ocular disorders associated with 14 angiogenesis which may be treated using the methods and antibody molecules of the invention include 16 corneal graft rejection, neovascularization 17 following injury or infection, rubeosis, diabetic 18 retinopathy, retrolental fibroplasia and neovascular 19 glaucoma, corneal diseases and macular degeneration.
21 The methods of the present invention may be used to 22 treat other angiogenesis-mediated disorders 23 including hemangioma, solid tumors, leukemia, 24 metastasis, telangiectasia, psoriasis, scleroderma, pyogenic granuloma, myocardial angiogenesis, Crohn's 26 disease, plaque neovascularization, coronary 27 collaterals, cerebral collaterals, arteriovenous 28 malformations, ischemic limb angiogenesis, corneal 29 diseases, retrolental fibroplasia, arthritis, diabetic neovascularization, peptic ulcer, 31 Helicobacter related diseases, fractures, keloids, 32 and vasculogenesis.

2 Specific disorders that can be treated, and 3 compounds and compositions for use in the methods of 4 the present invention, are described in more detail 5 below.

7 Ocular Disorders Mediated by Angiogenesis 9 Various ocular disorders are mediated by 10 angiogenesis, and may be treated using the methods 11 described herein. One example of a disease mediated 12 by angiogenesis is ocular neovascular disease, which 13 is characterized by invasion of new blood vessels 14 into the structures of the eye and is the most 15 common cause of blindness. In age-related macular 16 degeneration, the associated visual problems are 17 caused by an ingrowth of choroidal capillaries 18 through defects in Bruch's membrane with 19 proliferation of fibrovascular tissue beneath the 20 retinal pigment epithelium. In the most severe form 21 of age-related macular degeneration (known as "wet"
22 ARMD) abnormal angiogenesis occurs under the retina 23 resulting in irreversible loss of vision. The loss 24 of vision is due to scarring of the retina secondary 25 to the bleeding from the new blood vessels. Current 26 treatments for "wet" ARMD utilize laser based 27 therapy to destroy offending blood vessels.

28 However, this treatment is not ideal since the laser 29 can permanently scar the overlying retina and the 30 offending blood vessels often re-grow. An 31 alternative treatment strategy for macular 1 degeneration is the use of antiangiogenesis agents 2 to inhibit the new blood vessel formation or 3 angiogenesis which causes the most severe visual 4 loss from macular degeneration.
6 Other conditions associated with or caused by 7 angiogenic damage for which the present invention 8 may be used include diabetic retinopathy, 9 retinopathy of prematurity, corneal graft rejection, neovascular glaucoma and retrolental fibroplasia, 11 diseases associated with corneal neovascularization 12 including, but are not limited to, epidemic 13 keratoconjunctivitis, Vitamin A deficiency, atopic 14 keratitis, superior limbic keratitis, pterygium keratitis sicca, and periphigoid radial keratotomy, 16 diseases associated with retinal/choroidal 17 neovascularization including, but are not limited 18 to, macular degeneration, presumed myopia, optic 19 pits, chronic retinal detachment, hyperviscosity syndromes, trauma and post-laser complications.
21 Other diseases which may be treated using the 22 invention include, but are not limited to, diseases 23 associated with rubeosis (neovascularization of the 24 angle) and diseases caused by the abnormal proliferation of fibrovascular or fibrous tissue 26 including all forms of proliferative 27 vitreoretinopathy, neovascular glaucoma, 28 retinoblastoma, retrolental fibroplasia, rubeosis, 29 uveitis, and corneal graft neovascularization other eye inflammatory diseases, ocular tumors, and 31 diseases associated with choroidal or iris 32 neovascularization.

2 Inflammation 4 The antibody molecules and methods of the invention may be used in the treatment of inflammation. By 6 blocking the activity of CatS, the antibody 7 molecules may prevent proper antigen presentation in 8 `inflammed' cells and thus dampen the inflammatory 9 effects.
11 In such an embodiment, the antibody will ideally be 12 taken into the cell to enter the lysosome. Thus 13 targetting methods common in the art may be used.
14 As shown in the Examples, from the pH binding experiments, the inventors have demonstrated that 16 the antibody will bind even at pH 4.9, suggesting 17 that it may be effective in the lysosome.

19 The methods of the invention may also be used to treat angiogenesis associated inflammation, 21 including various forms of arthritis, such as 22 rheumatoid arthritis and osteoarthritis.

24 Further, in these methods, treatment with combinations of the compounds described herein with 26 other agents useful for treating the disorders is 27 provided. Such agents include, for instance, 28 cyclooxygenase-2 (COX-2) inhibitors, which are well 29 known to those of skill in the art.

1 The blood vessels in the synovial lining of the 2 joints can undergo angiogenesis. The endothelial 3 cells form new vascular networks and release factors 4 and reactive oxygen species that lead to pannus growth and cartilage destruction. These factors are 6 believed to actively contribute to rheumatoid 7 arthritis and also to osteoarthritis. Chondrocyte 8 activation by angiogenic-related factors contributes 9 to joint destruction, and also promotes new bone formation. The methods described herein can be used 11 as a therapeutic intervention to prevent bone 12 destruction and new bone formation.

14 Pathological angiogenesis is also believed to be involved with chronic inflammation. Examples of 16 disorders that can be treated using the methods 17 described herein include ulcerative colitis, Crohn's 18 disease, bartonellosis, and atherosclerosis.

Pharmaceutical Compositions 22 The antibody molecules and nucleic acids may be 23 administered as a pharmaceutical composition.
24 Pharmaceutical compositions according to the present invention, and for use in accordance with the 26 present invention may comprise, in addition to 27 active ingredients, a pharmaceutically acceptable 28 excipient, a carrier, buffer stabiliser or other 29 materials well known to those skilled in the art (see, for example, (Remington: the Science and 31 Practice of Pharmacy, 21St edition, Gennaro AR, et 32 al, eds., Lippincott Williams & Wilkins, 2005.).

1 Such materials may include buffers such as acetate, 2 Tris, phosphate, citrate, and other organic acids ;
3 antioxidants; preservatives; proteins, such as serum 4 albumin, gelatin, or immunoglobulins ; hydrophilic polymers such aspolyvinylpyrrolidone ; amino acids 6 such as glycine, glutamine, asparagine, histidine, 7 arginine, or lysine ; carbohydrates; chelating 8 agents; tonicifiers; and surfactants.

The pharmaceutical compositions may also contain one 11 or more further active compound selected as 12 necessary for the particular indication being 13 treated, preferably with complementary activities 14 that do not adversely affect the activity of the antibody molecule, nucleic acid or composition of 16 the invention. For example, in the treatment of 17 cancer, in addition to an anti CatS antibody 18 molecule of the invention, the formulation may 19 comprise an additional antibody which binds a different epitope on CatS, or an antibody to some 21 other target such as a growth factor that e.g.
22 affects the growth of the particular cancer, and/or 23 a chemotherapeutic agent.

For example, in one embodiment, combination therapy 26 employing a specific binding agent of the invention 27 and an agent which inhibits, for example vascular 28 endothelial growth factor (VEGF) may be used.

Suitably, combination therapy employing a specific 31 binding agent of the invention and an agent which 32 inhibits EGF receptor, PDGF(3, thrombin, bFGF, VEGFR

1 kinase, fibroblast growth factor, tubulin, VEGF-A, 2 or placental growth factor may be used.

4 In particular embodiments, combination therapy 5 including at least an antibody molecule of the 6 invention and two, three, or more agents in 7 combination may be used.

9 In particular embodiments, a combination therapy 10 employing a antibody molecule of the invention and 11 an agent selected from EvizonT"', PTK787, RetaaneTM, 12 AG-13958, CAND5, CombretastatinTM or VEGF TrapTM may 13 be used.

15 By employing combination therapy targeting at least 16 two distinct pathways or mechanisms, improved 17 efficacy, for example a synergistic effect, may be 18 obtained.

20 The active ingredients (e.g. antibody molecules 21 and/or chemotherapeutic agents) may be administered 22 via microspheres, microcapsules liposomes, other 23 microparticulate delivery systems. For example, 24 active ingredients may be entrapped within 25 microcapsules which may be prepared, for example, by 26 coacervation techniques or by interfacial 27 polymerization, for example, hydroxymethylcellulose 28 or gelatinmicrocapsules and poly-29 (methylmethacylate) microcapsules, respectively, in 30 colloidal drug delivery systems (for example, 31 liposomes, albumin microspheres, microemulsions, 32 nano-particles and nanocapsules) or in 1 macroemulsions. For further details, see Remington:
2 the Science and Practice of Pharmacy, 21St edition, 3 Gennaro AR, et al, eds., Lippincott Williams &
4 Wilkins, 2005.
6 Sustained-release preparations may be used for 7 delivery of active agents. Suitable examples of 8 sustained-release preparations include semi-9 permeable matrices of solid hydrophobic polymers containing the antibody, which matrices are in the 11 form of shaped articles, e. g. films, suppositories 12 or microcapsules. Examples of sustained-release 13 matrices include polyesters, hydrogels (for example, 14 poly (2-hydroxyethyl-methacrylate), or poly (vinylalcohol)), polylactides (U. S. Pat. No. 3, 16 773, 919), copolymers of L-glutamic acid andy ethyl-17 Lglutamate,non-degradable ethylene-vinyl acetate, 18 degradable lactic acid-glycolic acid copolymers, and 19 poly-D- (-)-3-hydroxybutyric acid.
21 As described above nucleic acids of the invention 22 may also be used in methods of treatment. Nucleic 23 acid of the invention may be delivered to cells of 24 interest using any suitable technique known in the art. Nucleic acid (optionally contained in a 26 vector) may be delivered to a patient's cells using 27 in vivo or ex vivo techniques. For in vivo 28 techniques, transfection with viral vectors (such as 29 adenovirus, Herpes simplex I virus, or adeno-associated virus) and lipid-based systems (useful 31 lipids for lipid-mediated transfer of the gene are 32 DOTMA, DOPE and DC-Chol, for example) may be used 1 (see for example, Anderson et al., Science 256 2 808-813 (1992). See also WO 93/25673 4 In ex vivo techniques, the nucleic acid is introduced into isolated cells of the patient with 6 the modified cells being administered to the patient 7 either directly or, for example, encapsulated within 8 porous membranes which are implanted into the 9 patient (see, e. g. U. S. Patent Nos. 4, 892, 538 and 5, 283, 187). Techniques available for 11 introducing nucleic acids into viable cells may 12 include the use of retroviral vectors, liposomes, 13 electroporation, microinjection, cell fusion, DEAE-14 dextran, the calcium phosphate precipitation method, etc.

17 The antibody molecule, agent, product or composition 18 may be administered in a localised manner to a 19 tumour site or other desired site or may be delivered in a manner in which it targets tumour or 21 other cells. Targeting therapies may be used to 22 deliver the active agents more specifically to 23 certain types of cell, by the use of targeting 24 systems such as antibody or cell specific ligands.
Targeting may be desirable for a variety of reasons, 26 for example if the agent is unacceptably toxic, or 27 if it would otherwise require too high a dosage, or 28 if it would not otherwise be able to enter the 29 target cells.
31 Dose 1 The antibody molecules, nucleic acids or 2 compositions of the invention are preferably 3 administered to an individual in a "therapeutically 4 effective amount", this being sufficient to show benefit to the individual. The actual dosage 6 regimen will depend on a number of factors including 7 the condition being treated, its severity, the 8 patient being treated, the agent being used, and 9 will be at the discretion of the physician.
11 The optimal dose can be determined by physicians 12 based on a number of parameters including, for 13 example, age, sex, weight, severity of the condition 14 being treated, the active ingredient being administered and the route of administration.

17 As a rough guideline, doses of antibodies may be 18 given in amounts of lng/kg- 500mg/kg of patient 19 weight.
21 Assays 23 The antibody molecules of the present invention may 24 further be used in diagnostic assays to determine the presence of cathepsin or cathepsin S expressing 26 cells in a biological sample. Thus the invention 27 further extends to use of the antibody molecule of 28 the invention in a diagnostic method.

In one embodiment, the invention provides a method 31 for determining the presence of cell expressing 32 cathepsin S in a biological sample, said method 1 comprising contacting the biological sample with an 2 antibody molecule of the invention and determining 3 binding of the antibody molecule to the biological 4 sample, wherein binding of the antibody molecule to the biological sample relative to a control is 6 indicative of the presence of cathepsin S.

8 The antibody molecules may also be used in the 9 diagnosis of a variety of conditions and disorders associated with Cathepsin S expression or activity.
11 Such methods form another aspect of the invention.

13 In one embodiment, the invention provides an assay 14 method for detecting a cathepsin S associated condition or disease, e.g. cancer, in a subject, 16 comprising:
17 (a) providing a biological sample from the subject, 18 (b) contacting the biological sample with an 19 antibody molecule of the invention (b) determining a level of binding of the antibody 21 to the biological sample, wherein an elevated level 22 of binding of the antibody to the biological sample 23 relative to a control sample is indicative of the 24 presence of said disease.
26 The the invention may be used to monitor disease 27 progression, for example using biopsy samples at 28 different times. In such embodiments, instead of 29 comparing the expression of cathepsin S against a control sample from e.g. a different tissue source 31 known not have enhanced cathepsin S expression, the 32 expression of the cathepsin S is compared against a 1 biological sample obtained from the same tissue at 2 an earlier time point, for example from days, weeks 3 or months earlier.

5 Any suitable biological sample may be used in the 6 invention; the nature of the disease or condition 7 may determine the nature of the sample which is to 8 be used in the methods of the invention. The sample 9 may be, for example, a sample from a tumour tissue 10 biopsy, bone marrow biopsy or circulating cells in 11 e.g. blood. Alternatively, e.g. where for example 12 the methods are being used to diagnose or monitor a 13 gastrointestinal tumour, tumour cells may be 14 isolated from faeces samples. Other sources of 15 biological sample may include plasma, serum, 16 cerebrospinal fluid, urine, interstitial fluid, 17 ascites fluid etc.

19 For example, solid tumour samples may be collected 20 in complete tissue culture medium with antibiotics.
21 Cells may be manually teased from the tumour 22 specimen or, where necessary, are enzymatically 23 disaggregated by incubation with collagenase/DNAse 24 and suspended in appropriate media containing, for 25 example, human or animal sera.

27 In other embodiments, biopsy samples may be isolated 28 and frozen or fixed in fixatives such as formalin.
29 The samples may then be tested for expression levels 30 of genes at a later stage.

1 The invention further extends to diagnostic kits for 2 use in the detection of cathepsin S. Thus, in one 3 embodiment, the invention extends to a kit for the 4 diagnosis of the presence of cathepsin S, the kit comprising one or more antibody molecules of the 6 invention, or one or more polypeptides of the 7 invention.

9 Any suitable assay methods and kits may be used.
These include but are not be limited to ELISA, 11 Immunohistochemistry, Electron Microscopy, Latex 12 agglutination, lateral flow immunoassays, Immuno 13 Blotting and Dip Stick Immuno testing.

The invention will now be described further in the 16 following non-limiting examples. Reference is made 17 to the accompanying drawings in which:

19 Figure 1 shows photographs of HMEC cells cultured in vehicle only control, an isotype control, an anti 21 cathepsin S antibody (mAbl), or an anti cathepsin S
22 antibody (mAb2);

24 Figure lb illustrates graphs illustrating the inhibition of capillary cell branching observed in 26 the presence of lEll (upper panel) or 1E4 (lower 27 panel);

29 Figure 2a illustrates photographs of sections of aorta cultured in the presence of a control antibody 31 and anti cathepsin S antibody lEll at 60, 300 and 1 600nM concentrations;

3 Figure 2b (top left) illustrates a graph summarising 4 the effect of the antibody on vessel length as shown in Figure 2a;

7 Figure 2b (top right) illustrates a graph 8 summarising the effect of the antibody on vessel 9 number as shown in Figure 2a;
11 Figure 2b (bottom) illustrates a graph summarising 12 the effect of the antibody on maximum vessel length 13 as shown in Figure 2a;

Figure 3a illustrates photographs of sections of 16 aorta cultured in the presence of a control antibody 17 and anti cathepsin S antibody IE11 at lug/ml, 18 5ug/ml, lOug/ml, and 100ug/ml, lug/ml 19 concentrations;
21 Figure 3b illustrates a graph summarising the effect 22 of the antibody in the experiment illustrated in 23 Figure 3a on number of tubules, mean tubule length 24 and maximum tubule length;
26 Figure 4 illustrates the results of an invasion 27 assay demonstrating attenuation of HCT116 tumour 28 invasion when treated with CatS lEll or 1E4;

Figure 5 illustrates CD34 staining of control 31 treated HCT116 tumours;

1 Figure 6 illustrates CD34 staining of CatS lEll 2 treated HCT116 tumours;

4 Figure 7 illustrates analysis of CatS RNA expression in leukaemia cell lines (HEL, NB4 & U937). RNA
6 levels were analysed following 40 cycles of PCR to 7 determine target expression; and 9 Figure 8 illustrates western blot analysis of CatS
expression in leukaemia cell lines (HEL, NB4 &
11 U937). Protein levels were analysed in whole cell 12 lysates using 1E4 Anti CatS.

14 Methods 16 Capillary-Like Tube Formation Assay 18 The effect of the CatS mAb on endothelial cell tube 19 formation was assessed as follows. Two hundred microliter of Matrigel (10 mg/ml) was applied to 21 pre-cooled 48-well plates, incubated for 10 min at 22 4 C and then allowed to polymerize for 1 h at 37 C.
23 Cells were suspended in endothelial growth cell 24 medium MV (Promocell), containing 200 nM of the appropriate antibody. Five hundred microliter 26 (1 x 105 cells) were added to each well. As 27 controls, cells were incubated with vehicle-only 28 control medium containing the appropriate volumes of 29 PBS. After 24 h incubation at 37 C and 5% C02, cells were viewed using a Nikon Eclipse TE300 microscope.

32 Cell viability and proliferation assays 2 Cytotoxic and proliferative effects of the CatS
3 monoclonal antibody on U251mg astrocytoma cells can 4 be tested as previously described. Briefly, cells are added to a final concentration of 1 x 104 6 cells/200 pl per well of a 96-well microtiter plate 7 (Corning Costar). Appropriate concentrations of 8 monoclonal antibody (100 nM) or vehicle-only control 9 media are added. Plates are incubated at 37 C and 5%
CO2for 24, 48, 72 and 96 hrs respectively. After 11 incubation, 10 l of 10 mg/ml MTT is added and 12 incubated for a further 2 h at 37 C and 5% CO2. The 13 medium is carefully removed and formazan crystals 14 dissolved in 100 pl/well of DMSO. Absorbance is measured as described above and the results 16 expressed as the percentage of cell viability and 17 proliferation relative to each vehicle-only control.
18 All tests are performed in quadruplicate.

Wound Assay 22 The in vitro migration assay used in these studies 23 is a modified version of the method described by 24 Ashton et al (1999). HMEC-1 is plated into individual chambers on a glass slide and grown to 26 90% confluence overnight. The medium is removed and 27 the monolayer wounded. The monolayer is re-28 supplemented with fresh medium and the required 29 volume of antibodies added to give the required final concentration.

1 Slides are removed at fixed time points until 2 complete closure of the wound, then fixed in 4% PBS
3 buffered paraformaldehyde. The extent of "wound"
4 closure is blindly assessed microscopically by an 5 independent investigator and quantified using a 6 calibrated eyepiece graticule (lmm/100 m graduation) 7 at 20x magnification (Olympus BX 50). The extent of 8 closure in the antibody treated slides is compared 9 to time matched sham treated controls and the %
10 inhibition of wound closure compared to time matched 11 controls calculated.

13 Rat Aorta Model 15 Male Wistar rats are euthanised and the thoracic 16 aorta is aseptically removed and sectioned into 1 cm 17 thick rings. The rings are washed ten times in 18 sterile medium to remove any bacteria and embedded 19 into Matrigel on 24 well plates. The wells are 20 supplemented with 2ml of medium and increasing 21 concentrations of antibodies. The plate is incubated 22 for 8 days and post incubation the Matrigel and 23 rings are fixed in 4% PBS buffered paraformaldehyde 24 and stored in PBS. The extent of vessel development 25 is blindly assessed microscopically by an 26 independent investigator and quantified using a 27 calibrated eyepiece graticule (lmm/100 m graduation) 28 at 20x magnification (Olympus BX 50). The extent of 29 vessel length, maximum vessel length and number of 30 vessels in each field of view is measured and 31 compared to time matched sham controls and the %
32 inhibition calculated.

3 RT-PCR was performed using a DNA Engine Tetrad 2 4 thermal cycler (Biorad). RNA was collected from leukaemia cell pellets using the RNA STAT-60 reagent 6 (Tel-Test Friendswood, USA) according to the 7 manufacturers instructions and cDNA synthesised 8 using lug RNA and a reverse transcriptase kit (GIBCO
9 Invitrogen, Paisley, UK). The primer sets used for RT-PCR were CatS forward primer 5'- ACT CAG AAT GTG
11 AAT CAT GGT G-3' and CatS reverse primer 5'-TTC TTG
12 CCA TCC GAA TAT ATC C-3'. Gene expression was 13 analysed using a biomix PCR mixture (Bioline, UK) 14 containing 25u1 Biomix; 1.5ul forward primer; 1.5ul reverse primer; 2ul cDNA; 20ul dH20. PCR conditions 16 consisted of an initial denaturation step of 95 C
17 for 10 minutes, followed by either 40 cycles of 95 C
18 for 30 sec; 55 C for 30 sec; 72 C for 90 sec, with a 19 final extension of 72 C for 10 minutes. 5ul of amplified product was loaded onto a 1.5% agarose gel 21 (0.001% ethidium bromide) which was ran at 90V for 22 40 minutes prior to analysis on a UV box.

23 Western Blotting Cells were washed in PBS (5 minute centrifugation at 26 1500rpm) prior to lysis with RIPA buffer containing 27 a protease inhibitor cocktail (Calbiochem, UK) as 28 previously described. Whole cell lysates were loaded 29 onto 12% SDS-PAGE gels at equal concentrations. Gels were run overnight at 50V prior to semi-dry transfer 1 onto nitrocellulose membrane at 20V for 45 minutes 2 (BioRad, UK). The nitrocellulose membrane was 3 blocked using in PBS (3% Milk powder) for -1 hour, 4 and washed x 3 with PBS (0.01% tween) for 5 minutes.
The membrane was then probed with a 1 in 200 6 dilution of CatS Mab 1E4 Mab in PBS (3% Milk powder) 7 for 1 hour. The membrane was washed x 3 with PBS
8 (0.01% tween) for 10 minutes prior to the addition 9 of a 1 in 5000 dilution of secondary goat anti mouse-HRP conjugated antibody (BioRad, UK) in PBS
11 (3% Milk powder) for 1 hour. This was then washed 12 three times in PBS (0.01% tween) for 10 minutes 13 each. The membrane was 'developed' by ECL (enhanced 14 chemi-luminescence) using the Super Signal kit (Pierce). The membrane was incubated in ECL solution 16 for 5 minutes, prior to analysis using a kodak Gel 17 logic 1500 imaging system (Kodak) 19 Immunohistochemistry 21 Paraffin embedding of formalin-fixed xenograft 22 tissue samples was performed as previously 23 described. Immunostaining was performed using the 24 avidin-horseradish peroxidase method (Vectorlabs ABC
Elite Kit).

27 Briefly, sections were deparaffinised by passing 28 from histoclear to alcohol to running water.
29 Sections were then boiled in citrate buffer, pH6.0, for 22 min. Endogenous peroxidase activity was 31 blocked by incubation in 3% H202 in methanol for 13 1 min. Incubation in 10% normal rabbit serum blocking 2 solution was carried out for 1 hour at room temp.
3 Sections were incubated with primary rat anti human 4 CD34 (Abcam) at a 2ug/ml concentration at 4 C
overnight. Appropriate isotype controls were used at 6 the same dilutions as primary antibodies.

8 For peroxidase staining, sections were incubated 9 with biotinylated rabbit anti rat secondary antibody (Vector Laboratories) for 30 min at room temp 11 followed by incubation with the Vectastain Elite ABC
12 reagent (Vector Laboratories) for a further 30 min 13 at room temp. For visualisation sections were 14 stained with 3,3'-diaminobenzidine and counterstained with Gill's II hematoxylin solution.
16 Sections were analyzed using a Nikon Eclipse 80i 17 camera 19 Invasion Assay 21 In-vitro invasion assays were performed using a 22 modified Boyden chamber with 12 pm pore membranes.
23 The upper membrane surface was coated with Matrigel 24 (100 g/cm2) and allowed to dry overnight in a laminar flow hood. Cells were added (5 x 105 cells 26 in 500 l of serum free media) in the presence of 27 pre-determined concentrations of the appropriate 28 antibody and recombinant protein. Fresh complete 29 media was added to the lower chambers (1.5 mls), supplemented with the same concentration of the 31 antibody or recombinant protein as was applied to 32 the corresponding well above. All assays were 1 carried out in triplicate and invasion plates were 2 incubated at 37 C and 5% CO2 for 24 hours.

4 Cells remaining on the upper surface of the membrane were removed by wiping with cotton tips and cells 6 which had invaded through were fixed in Carnoy's 7 fixative for 15 minutes. After drying, the nuclei of 8 the invaded cells were stained with Hoechst 33258 9 (50 ng/ml) in PBS for 30 minutes at room temperature. The chamber insert was washed twice in 11 PBS, mounted in PermaFluor mounting medium and 12 invaded cells were viewed with a Nikon Eclipse TE300 13 fluorescent microscope. Ten digital images of 14 representative fields from each of the triplicate membranes were taken using a Nikon DXM1200 digital 16 camera at magnification of x20. The results were 17 analysed using Lucia GF 4.60 by Laboratory Imaging 18 and were expressed as a percentage of invaded cells 19 compared to controls.
21 Results and Discussion 23 Example 1. CatS Antibodies can inhibit tube-like 24 formation in human endothelial cells 26 Using the Matrigel morphogenesis assay described by 27 (Grant DS, Tashiro K, Segui-Real B, Yamada Y, Martin 28 GR, Kleinman HK.Two different laminin domains 29 mediate the differentiation of human endothelial cells into capillary-like structures in vitro.
31 Cell. 1989 Sep 8;58(5):933-43.), capillary-tubule 32 formation assays were performed with human 1 microvascular endothelial cells (HMECs) cultured on 2 Matrigel enabling the endothelial cells form tube-3 like structures, with invasive sprouts extending 4 from individual cells to form contacts with nearby 5 endothelial cells. Figure la illustrates the results 6 when the HMEC cells were cultured in the presence of 7 two CatS antibodies(lEll and 1E4) or isotype 8 control. Extensive tube-like structures are evident 9 in the vehicle-only control and isotype control 10 antibody (200 nM) panels; however this tube 11 formation is almost completely abolished in the 12 presence of the lEll or 1E4 antibodies (200 nM).
13 These results were then quantified as shown in 14 Figure lb.
16 Both antibodies have been previously shown to bind 17 specifically to CatS with no cross-reactivity with 18 other cathepsins, in particular those with the 19 greatest homology to CatS. Antibodies lEll and 1E4 have both been characterised for their ability to 21 inhibit the catalytic activity of CatS; lEll can 22 specifically inhibit the activity of CatS whereas 23 1E4 has no discernable effect. Therefore, the 24 results from the capillary-tube assay would suggest that the sequestering of active CatS secreted from 26 the endothelial cells by either an inhibitory or 27 non-inhibitory CatS mAb is sufficient to prevent the 28 migration and arrangement of the endothelial cells 29 into tube-like structures.
31 Example 2. CatS antibodies can inhibit tube like 32 formation in rat aortic arch ex vivo model 2 To evaluate further the role of CatS in 3 angiogenesis, an ex vivo rat aortic arch assay was 4 performed. Sections of the aorta (1 mm) were cultured within a thin layer of Matrigel in the 6 presence of the inhibitory antibody and appropriate 7 controls. The formation of tube-like vessels from 8 the aorta were monitored and quantified after 7 days 9 by measuring the reduction in the number of vessels, mean vessel length and maximum vessel length 11 compared to controls.

13 Figure 2 illustrates the significant inhibition of 14 tube formation in the presence of the CatS lEll antibody. Photographs of the ring segments are shown 16 in Figure 2a with the results summarised in Figure 17 2b.Incubation of the rat aortic ring segments with 18 up to 600nM of lEll resulted in greater than 80%
19 reduction in total vessel number, mean vessel length and maximum vessel length (figure 2b).

22 Figure 3 illustrates the significant inhibition of 23 tube formation in a repeat experiment the presence 24 of the CatS lEll antibody. Photographs of the ring segments are shown in Figures 3a and 3b with the 26 results summarised in Figure 3c. Incubation of the 27 rat aortic ring segments with up to 10 g/ml of lEll 28 resulted in a 70% reduction in total vessel number 29 and a 60% reduction in both mean vessel length and maximum vessel length.

32 Example 3 2 To investigate the effect of the CatS antibodies on 3 tumour invasion, an invasion assay was performed as 4 described above using HCT116 cells. The results are shown in Figure 4. As can be seen, tumour invasion 6 was significantly attenuated in HCT116 cells treated 7 with the CatS lEll antibody and in HCT116 cells 8 treated with the 1E4 CatS antibody.

Example 4 Effect of treatment on vasculature of 11 HCT116 tumours treated with CatS antibody 13 The effect of treatment on the vasculature of HCT116 14 tumours treated with CatS antibody was investigated by staining CatS lEll treated HCT 116 tumours using 16 CD34 and comparing with HCT 116 tumours treated with 17 a control antibody. The results are shown in Figure 18 5 and Figure 6. As can be seen from Figure 5, in the 19 control treated tumours, vasculature was noted evidently at the periphery of the tumour (A-C (X4)).
21 Large number of small, functionally limited blood 22 vessels present, with some larger vessels also 23 determined (D-E (X20)). However, as shown in Figure 24 6, in the CatS lEll treated HCT116 tumours, vasculature at the periphery of the tumours was 26 greatly reduced (A-C (X4)) and the number of vessels 27 presented was lower compared to the control treated 28 tumours.

Example 5 CatS 1E4 bind CatS from leukaemia cell 31 lines 1 CatS RNA was amplified from three different 2 leukaemia cell lines and a positive control. RNA
3 levels were analysed following 40 cycles of PCR to 4 determine target expression. As can be seen from Figure 7, CatS RNA was expressed by each of the 6 three leukaemia cell lines.

8 Further a Western blot was performed on whole cell 9 lysates of the three leukaemia cell lines using the 1E4 antibody. As shown in Figure 8, the CatS 1E4 11 binds to the Cat S protein, showing that it can be 12 used to target cathepsin S in leukaemia cells.

14 Example 6 Identification of the cathepsin S binding region to which the 1E4 antibody specifically binds 17 CatS specific primers were designed to contain a 5' 18 T7 promoter region and either a 5' or 3' 19 hexahistidine tag. Using standard conditions, these primers were used to amplify multiple different 21 regions of the CatS CDS before analysis by agarose 22 electrophoresis. Neat, unpurified PCR products were 23 then added to 50 l aliquots of wheat germ cell-free 24 lysate(Rapid Translation System, Roche) and incubated overnight at room temperature. These 26 protein lysates were then electrophoresed and 27 western blotted using standard techniques.

29 After blocking in 3% milk powder in PBS, pH 7.4 (w/v), CatS antibodies (1 in 200 dilution in PBS) 31 were incubated overnight at 4 C. Specific binding 32 of the CatS antibodies to the blot was visualised by 1 washing and detection with a secondary anti-mouse -2 HRP conjugate by chemoillumenscence following 3 standard protocols. Verification of protein 4 expressed was afforded by re-probing of these blots with anti-histidine tag monoclonal antibody -HRP
6 conjugate (Sigma-Aldrich).

8 By determining to which of the multiple samples the 9 CatS antibodies bound, the binding region was identified as having the amino acid sequence as 11 shown as Sequence ID No: 1:

All documents referred to in this specification are 16 herein incorporated by reference. Various 17 modifications and variations to the described 18 embodiments of the inventions will be apparent to 19 those skilled in the art without departing from the scope and spirit of the invention. Although the 21 invention has been described in connection with 22 specific preferred embodiments, it should be 23 understood that the invention as claimed should not 24 be unduly limited to such specific embodiments.
Indeed, various modifications of the described modes 26 of carrying out the invention which are obvious to 27 those skilled in the art are intended to be covered 28 by the present invention.

Claims (29)

1. A method of inhibiting angiogenesis in a group of cells, a tissue or an organ, said method comprising administration of an antibody molecule or nucleic acid encoding the antibody molecule to said cells, tissue or organ, wherein said antibody molecule specifically binds cathepsin S but does not inhibit the proteolytic activity of cathepsin S.

2. A method of treating a condition associated with activity of Cathepsin S in a patient in need of treatment thereof, said method comprising administration of an antibody molecule or nucleic acid encoding the antibody molecule to said patient, wherein said antibody molecule specifically binds cathepsin S but does not inhibit the proteolytic activity of cathepsin S.

3. The method according to claim 2, wherein said condition is associated with aberrant expression of cathepsin S.

4. The method according to claim 2 or claim 3, wherein said condition is associated with angiogenesis.

5. The method according to any one of claims 2 to 4, wherein said condition is cancer.

6. The method according to any one of claims 2 to 4, wherein said condition is an inflammatory condition.

7. The method according to any one of claims 2 to 4, wherein said condition is an ocular disease.

8. The method according to any one of claims 2 to 4, wherein said condition is atherosclerosis.

9. An isolated polypeptide, wherein said polypeptide consists of a polypeptide sequence having at least 60% homology to Sequence ID No: 1.

10. The isolated polypeptide according to claim 9, wherein the said polypeptide consists of a polypeptide sequence having the amino acid sequence shown as Sequence ID No: 1.

11. An antibody molecule which specifically binds cathepsin S and which inhibits angiogenesis but does not inhibit the proteolytic activity of cathepsin S.

12. The antibody molecule according to claim 11, wherein said antibody molecule has binding specificity for the polypeptide of claim 9 or claim 10.

13. The method according to any one of claims 1 to 8, wherein said antibody molecule is the antibody molecule according to claim 12.

14. The antibody molecule according to claim 11 or claim 12, or a nucleic acid encoding said antibody molecule for use in medicine.

15. The use of an antibody molecule or nucleic acid encoding the antibody molecule wherein said antibody molecule specifically binds cathepsin S
but does not inhibit the proteolytic activity of cathepsin S in the preparation of a medicament for the treatment of a condition associated with activity of cathepsin S.

16. The use according to claim 15, wherein the antibody molecule is the antibody molecule according to claim 11 or claim 12.

17. The use according to claim 15 or claim 16, wherein said condition is associated with aberrant expression of cathepsin S.

18. The use according to claim 15 or claim 16, wherein said condition is associated with angiogenesis.

19. The use according to claim 18, wherein said condition is cancer.

20. The use according to claim 18, wherein said condition is an inflammatory condition.

21. The use according to claim 18, wherein said condition is an ocular disease.

22. The use according to claim 18, wherein said condition is atherosclerosis.

23. A pharmaceutical composition comprising the antibody molecule according to claim 11 or claim 12.

24. The pharmaceutical composition according to claim claim 23, wherein said composition further comprises an inhibitor of VEGF.

25. The pharmaceutical composition according to claim 24, wherein said inhibitor is an anti VEGF
antibody.

26. The pharmaceutical composition according to any one of claims 23 to 25claim 2, wherein said composition further comprises an inhibitor of EGF
receptor.

27. The pharmaceutical composition according to claim 26, wherein said inhibitor is an anti EGF
receptor antibody.

28. A method for determining the presence of cathepsin S in a biological sample, said method comprising contacting the biological sample with an antibody according to claim 11 or claim 12 and determining binding of the antibody molecule to the biological sample, wherein binding of the antibody molecule to the biological sample relative to a control is indicative of the presence of cathepsin S.

29. An assay method for detecting a tumour in a subject, comprising:

(a) providing a biological sample from the subject, (b) contacting the biological sample with an antibody molecule according to claim 11 or claim (b) determining a level of binding of the antibody to the biological sample, wherein an elevated level of binding of the antibody to the biological sample relative to a control sample is indicative of the presence of a tumour.